Expansion joint



Sept. 5, 1933. R. HALL 1,925,003

EXPANSION JOINT Filed Aug. 25, 1932 ou H `\\\\\\\\\fum| Y Syvum/vio@Patented Sept. 5, 1933 UNHTED STATES PATENT OFFE'CE Application AugustZ5, 1932. Serial No. 630,472v

Claims.

This invention relates to expansion structures adapted to use in steamand similar systems wherein it is necessary to make provision forshifting, expansion and contraction of the sec- 1 5 tions of pipe linesand conduits under changes in the conditions under which they operate.

The invention has particular reference to the type of expansion jointknown as slip joints which comprise a plurality of members associatcdfor relative sliding movement one within the other and which is providedwith a nonmetallic packing adapted to seal the joint against leakage. Inknown structures of this character, the packing deteriorates with useand allows the joint to leak. Also, particularly in joints employed inhigh pressure lines, the packing has a vtendency to blow out because ofthe pressure difference between the inside and outside of the line. Inrenewing the packing when occasion requires it is ordinarily rstnecessary that the operation of the section of the pipe line in whichthe joint is located be discontinued, since leakage and line pressurewill interfere generally with the repair work, and the seating andadjustment of anew packing so as to provide a leak-proof seal cannotproperly be carried out.

The present invention provides an improved v construction for expansionstructures not subject to the disadvantages and objections such as thosejust referred, and which will increase the life and efficiency of theconventional packing and minimize the danger of the same blowing out,provide a more eifective seal against leakage in the joint and enablethe same to operate successfully under high pressures as well as underlow and moderate pressures, and enable the joint packing to be removedand renewed readily and without interruption to the operation of thejoint or the pipe system. Accordingly, sealing means are associated withone of the sliding members of the expansion structure additional to theconventional packing, and interposed between the packing and the innerend of the inner member of the joint so as to relieve the packing ofpart of its leak-preventing function and lessen its exposure to moistureand pressure which deteriorate v the same and cause it to leak and blowout.

A further important feature of the invention is that the sealing meansand outer packing are associatedr with the telescopic joint members insuch manner so that a stop maybe provided interiorally of the joint tolimit the longitudinal movement of the joint members, the arrangementbeing such that the packing will yieldingly support a stop and thusprevent strain on the joint under sudden movement between the members.

The supplemental sealing means is preferably in the form of one or moremetallic rings similar to those used in association with the pistons ofinternal combustion and other engines, such character elements beingparticularly adapted to withstand the destructive iniiuences abovereferred to. Suchelements are installed between the adjacent walls ofthe respective sliding members of the joint, one of the members beinggrooved to provide a retaining seat such as will hold the rings againstmovement under operation of the joint, and the other being nicelymachined to enable the rings to slide relative thereto while maintaininga sealing contact. To provide an eifective seal the rings should beresilient in character. If they are to be associated with the outerjoint member they should be formed so as to have a tendency to contractin order that they may make sealing contact with the inner slidingmember; if, as may be found more convenient, the rings are to beassociated with the inner member and to have sliding contact with theouter joint member they should possess a tendency to expand.

To further facilitate the renewal of the conventional packing and toguard against the building up of any moisture or pressure at the packingseat in case the supplementary sealing means is not-as may well be thecase at times under unfavorable conditions-entirely leakproof, it isfurther proposed, according to my invention, to locate a blow ofibetween the packing and the sealing means which may be opened when thenew packing is being installed. Of course, the supplementary sealingYmeans will prevent any substantial leakage towards the packing evenwhen the pipe line is operating under heavy load, and such slightleakage as may occur will be conducted outside the joint by the blow offwithout affecting the installation of the new packing or rendering itnecessary to interrupt the operation of the line while such work isgoing on.

To provide an internal stop which takes ad.- vantage of the resiliencyof the packing to prevent strain on the joint, the joint members arevaried in diameter at diiierent portions of their length. The outerjoint member is provided with an annular chamber of enlarged diameteradjacent its end adapted to receive a ring which will form a stopadapted to coact with a shoulder formed on the inner joint member.

The conventional packing will be inserted behind the ring so as to forma cushion therefor in addition to serving its usual function of sealingthe joint. The inner joint member will be made of smaller diameter thanthe outer joint member and formed with an enlargement on its endcarrying the sealing means above described and presenting a shoulderadapted to coact with the stop ring disposed in the packing chamber. Theinternal stop may be used alone or in association with a conventionalstop located externally of the joint. In the latter event the internalstop will be arranged to engage the shoulder on the inner joint memberpreliminary to the time the external stop becomes perative Under sucharrangement the internal stop by reason of vits yielding support on thepacking will serve primarily to retard movement and prevent shock andstrain upon the joint members before and vwhen the external stopfunctions to bar any further movement of the joint members.

In order that the construction and operation of the expansion joint ofmy invention may be entirely clear, I will describe one embodimentthereof, reference being had in this connection to the accompanyingdrawing in which:

Fig. 1 is a View in longitudinal section illustrating a conventionaltypeof expansion structure with my inventionV embodied therein;

Fig. 2 is a transverse section taken on line 2-2 of Fig. 1; and,

Fig. 3 is a perspective view of one type of sealing element which may beutilized in accordance with my invention.

Referring now to the drawing, I have shown therein` an expansionLstructure comprising a plurality of members telescopicaily arranged onewithin the other for relative longitudinal movement, the outer memberbeing designated 10 and the inner member 11, and having farther endsadapted to be connected intermediate the ends of pipe sections. The-boreof the outer member 10 is enlarged adjacent its -inner end to provide anannular packing-holding chamber l2 in which is received a mass orannular strips of packing 13, and against which the member l1 hasasliding movement.

The packing 13 is held within the chamber 12 Y by a gland-element 14arranged in operative aswithdrawing the gland-element from associationwith the outer joint member the packing can -be removed and renewed.

ToV insure free lsliding movement. of the joint members relative to eachother any suitable guiding means may be employed. I havey in Fig.

i 1 illustrated one type mechanism-*which has proved satisfactory, thesame Vbeing heretofore :known in the art and not being an essential partvof the present invention. vSuchmeans includes an annular extension 17securedto ythe end flange 16 of the outer joint member 10 and anenlargement or portion 18r screwed or otherwise secured to the exposedportion ofthe inner joint member 11, whichnhas. sliding contact with theinner vsurface of said annular element. Y With such an arrangementthe'joint members will, be

Leeaoos supported relative to each other at all times. The annularelement 1'7 may be provided with an annular inwardly extendingprojection 19 which will constitute a stop against which the enlargement18 of the inner member l1 will bear when the joint members have reachedtheir outer limit of expansion.

In order that the gland-element will be accessible the annular elementl'l is provided with openings such as 20 of sufficient size that aworkman may adjust or renew the packing without diniculty.

The construction so far described is conventional. I will now describethe application of my invention thereto. The inner joint member 11 ispreferably made of somewhat smaller diameter for the major portion ofits length than the inner diameter of the outer joint member 10. Thesame is, however, provided with an end portion 21 adapted to slidinglyengage the inner wall 22 of the outer joint member. The end 21 may beformed as a separate head and threaded on the joint member 1l as shownin the drawing. Since the head 2l is of larger diameter than that of themainr portion of the inner member a shoulder 23 will be formed, thepurposes of which will now be described. At the inner end of the annularpacking chamber l2 in the outer joint member is disposed a ring 24 whichseats against the shoulder 25 in said chamber. The inner periphery ofthe ringA is smaller in diameter than that of the inner periphery of thejoint member, and is substantially the same as the outer diameter of theinner joint member 11. With such arrangement it will be evident that theshoulder 23 on the head of the inner joint member will vengage the ring'when the two joint members are at the outer limit of their longitudinalmovement. The packing 13 besides forming a seal will bear against thering 24, by reason of its resilient character will yieldingly supportthe ring and allow the same to move longitudinally under pressureexerted by the shoulder. Such construction, in effect, provides acushioned stop which will prevent strain upon the joint when the jointmembers suddenly move to their extreme outer limit.

The head` 2l of the inner joint member is, as above stated, in closeysliding engagement with the inner wall 22 of the outer joint member,serving to support and guide the inner joint member in its slidingmovement. The main portion of the inner joint member ll being of smallerdiameter than the head may be guided by the gland-element 14 which forsuch purpose has an inner diameter substantially the same as that of theinner joint member. Thus the inner joint member is supported and guidedon both sides of the packing chamber 12.

When used with the external rigid stop including elements 18 and 19above described, the normal position of the internal stop ring 24 may besuch as to engage the shoulder 23 before the external stop becomesoperative as indicated in Figi. With such an arrangement the internalstop will not only act cooperatively with the external stop but willserve as a buffer as the ring 24 compresses the packing 13 to preventelements 18 and 19Y from Vcontacting with such force as might strain theparts of the joint.

Located between the inner wall 22 of the outer joint Vmember 10 and thehead 21 of .the inner ymember 11, inwardly of the packing 13, I providedsupplementary sealing means adapted to function in cooperation with thepacking and enabling thev packing to be renewed without rendering thejoint inoperative. Such means may comprise one or more metallicresilient rings 2S. To prevent the same from getting out of its properposition between the walls of the joint members during their slidingmovement, and to enable elements of satisfactory annular thickness to beused, one of the members is grooved as indicated at 27 to form a recessin which the sealing means may seat. The sealing means may thus besecured in association with one of the jointmembers and have aleak-proof sliding contact with the other member. In the embodimentillustrated, the

sealing means is secured in recesses in the headv of the inner jointmember 1l.

Between the supplemental sealing means 26 and the packing I3, anexpansion channel or groove 28 is provided in the inner wall of theouter joint member l0, the same being intended to receive any leakagewhich may occur at the supplemental sealing means and minimize anyunfavorable effect thereof against the packing.

A blow off plug 29 is also provided in the outer joint member, the samebeing conveniently located in line with the expansion channel 28. By solocating the plug between the packing and sealing means, it will beunderstood that the same may be removed at any time while the joint isin operation to exhaust any moisture or pressure which may have built upin the space between the packing and sealing means since the sealingmeans alone is effective to prevent any substantial leakage from theinterior of the joint.

The plug is preferably also removed when it is necessary to renew thepacking since it is desiraable that no pressure or moisture enter thepacking housing l2 or contact with new packing until the same is fullyinstalled and the gland-element bolted in place.

The outer end of the outer joint member l0 has a flange 30 for securingthe same to a pipe section, bolt holes 3l being provided for thispurpose. v

It will be evident that the novel construction of my invention greatlyimproves slip-type eXpansion joints by providing an additional sealingmeans which cooperates with the conventional packing in itsleak-preventing function, lengthens the life of the packing byminimizing the deteriorating influences ordinarily brought to bearthereon, and enables the packing to be renewed without making itnecessary to render the joint inoperative. The internal stop which incooperation with the resilient packing limits the longitudinal movementof the joint members without strain on the parts also materiallyincreases the desirability of the joint and enables it to be used underconditions where longitudinal movement is sudden and forceful.

It will be understood that my invention is capable of a considerablerange of modification and equivalency without departing from the salientfeatures thereof, so I do not intend to be limited in the practice of myinvention further than may i be required by the accompanying claims.

What I claim is:

l. An expansion joint comprising a plurality of annular membersassociated in close fitting contact one within the other for relativesliding movement, an enlargement in the bore of the outer memberadjacent the inner member, packing in the enlarged portion bearingagainst the inner member, a gland-element to hold the packing inposition and adapted to be removed to permit the withdrawal and renewalof the packing, a recess in one of the joint members adjacent the othermember located between the packlng and the interior of the joint,supplementary sealing means in said recess preventing directcommunication between the packing and the interior of the joint andadaptedto cooperate with the packing and permit the same to be withdrawnand renewed while the joint is in operation, a blow on located betweenthe packing and supplementary sealing means and adapted to be openedduring renewal of the packing to allow the escape of any leakage passingthe supplementary sealing means, and an annular channel in the outermember adjacent the inner member and connecting with the blow off.

2. An expansion joint having a plurality of members associated forrelative sliding movement one within the other, the outer joint memberbeing of enlarged bore adjacent its end to provide a packing chamber,compressible packing in said chamber forming a seal between the jointmembers, the inner joint member being of less diameter than the bore ofthe outer member and having an enlargement at its end providing ashoulder, a cushioned internal stop adapted to limit longitudinalbetween the joint members comprising a free ring engageable with theshoulder on the inner member located in the packing chamber, said ringbeing yieldingly supported by the packing so that it may give bycompressing the packing upon engagement with the shoulder, andadditional stop means located exteriorally of the joint, the cushionedstop being arranged to become operative under longitudinal movementbetween the joint members slightly before the external stop.

3, An expansion joint comprising a pair of pipe member slidable onewithin the other, the inner member being of less diameter than the boreof the outer member and being provided with an enlarged head makingbearing contact with the outer member and presenting a shoulder at theinner end of the head, sealing means between the head and the outermember in the form of one or more metallic rings carried in smallgrooves in the head, the outer member being of uniform bore for part ofits length and adjacent its end `being of enlarged bore to provide apacking chamber, flexible packing in the chamber forming a seal betweenthe outer member and the portion of the inner member beyond the enlargedhead, a gland element for compressing the packing, a rigid ring having alesser inner diameter than the bore of the outer member and coactivewith the shoulder on the head of the inner member yieldingly supportedin the inner end of the chamber by the packing, and an annular recess inthe outer member forming an expansion chamber located intermediate theinner and outer seals between the joint members and adjacent the packingq chamber, and a blow-off communicating with said recess.

4. An expansion joint comprising a pair of pipe members telescoping onewithin the other, the

outer member. being of uniform bore for the major portion of its length,the inner member being of lesser diameter than the bore of the outermember, a guide head of greater diameter than the inner member and ofsubstantial length in lecclose fitting sliding engagement with the boreof the outer member secured to the inner end of they outer joint membercarried in one or more peripheral grooves in the head, a packing chamberadjacent ther end of the outer joint member formedy by an enlargement inthe bore, flexible packing in the chamber forming a sealing between theouter member andthe portion of the inner member beyond thev guide head,a gland element vfor compressing the packing, and a rigid ring having alesser inner diameter than the bore of .the outer member and coaptivewith the shoulder on the head of theinner member yieldingly supported attheiinner end of the chamber by the packing.

5. An expansion joint comprising a pair of pipe members slidable onewithinthe other, the outer member being of uniform bore for the mainportion of its length, an enlarged guider and sealing head adaptedV toclosely t the bore of the outer member secured to the inner end of theinner member, said' head acting as an internal guide during movementbetween the joint members and having one or more peripheral recessescarrying rings which provide a seal between the inner and von the headof the inner member yieldingly supported in the inner end of the chamberby the packing, and additional guiding means for the joint memberscoactive with the internal guiding means provided by engaging portionsslidable with respect to each other located externally beyond the end ofthe packing chamber.

ROBERT HALL.

